1. Field of the Invention
This invention relates to a vehicle electronic key system for controlling permission for and the prohibition of an engine start according to a result of code matching by communication with a predetermined electronic key.
2. Description of the Related Arts
A wireless door locking system for locking and unlocking a vehicle door by a wireless portable has been suggested and the number of vehicles adopting it has increased. Moreover, some of these wireless door locking systems have additional functions. For example, a wireless portable having a function to set and reset an antitheft alarm, to open a trunk, and so on is known.
Furthermore, a handsfree smart entry system, in which an operator carries a card-type wireless portable (hereinafter referred to as an xe2x80x9celectronic keyxe2x80x9d) and a door lock is automaticaly released only at his/her approach to his/her vehicle, has been also suggested. According to such a system, an operator can always carry a card-type electronic key in, for example, his/her purse. It therefore maintains a high level of security based on communication, while it can reduce the trouble of operations necessary to release a door lock, etc.
Furthermore, for an engine start, security can also be improved by performing code matching procedures via communication. An immobilizer for achieving such a function has also been put to practical use. It is also preferable, therefore, that sending and receiving codes as an immobilizer function should be performed using an electronic key. Moreover, in an immobilizer communication takes place between a transmitter and a receiver usually installed in a key plate of an ignition key and an antenna installed on the peripheral part of a key cylinder.
When an electronic key is used, it can be used for code matching. According to Japanese Patent Laid-Open Publication No. Hei3-21575, an electronic key system in which an engine start is permitted via wireless communication with an electronic key carried by a user has been suggested.
Operations for an engine start, which have conventionally been performed by inserting an ignition key into a key cylinder, can also be performed with buttons of a card-type electronic key. Some users, however, want to perform operations for an engine start etc. by inserting a key as with a conventional ignition key, as is the same with conventional key operation etc. It is possible therefore to adopt the way of inserting a card-type electronic key, but some users want an electronic key having other shape than a card type. It also produces a problem: the shape of a place into which an electronic key is inserted must be changed.
It is an object of the present invention to provide an electronic key system which can control an engine start using electronic keys of various shapes.
According to the present invention, a vehicle electronic key system for performing code matching via communication with an electronic key and controlling permission for and the prohibition of an engine start according to a result of the matching comprises a rotary switch for an engine start and a keyhole connected to the rotary switch which the above electronic key can be inserted into, and the above electronic key inserted into the above keyhole makes the above rotary switch turnable.
As stated above, operations for an engine start are performed by inserting an electronic key into a keyhole and turning a rotary switch with this electronic key. These operations themselves are the same as those using a standard ignition key, which enables a user to operate without having a sense of incompatibility.
Furthermore, it is preferable that whether the above inserting of an electronic key into a keyhole is performed or not, the above permission for an engine start via communication is given. As a result, code matching will be performed even if an electronic key is not inserted into a keyhole. An operator therefore can directly operate a rotary switch with it in his/her hand. Even if an operator carries an electronic key not matching the shape of a keyhole, it will not hinder him/her from operations themselves. Therefore, electronic keys of various shapes can be adopted and there is no need to change the shape of a keyhole according to that of an electronic key.
Moreover, it is preferable that the above electronic key is equipped with a high-power code transmitter and a transponder the power of which is lower than that of the code transmitter and that when the above electronic key is inserted into the above keyhole, code matching is performed using the above transponder.
It enables code matching using this transponder of low power consumption if an electronic key is inserted into a keyhole. The dissipation of a battery in an electronic key can therefore be reduced. Moreover, having two code matching methods causes code matching to be surely performed even if either one becomes unavailable.
It is also preferable that a rotary switch lock unit for mechanically locking the drive of the rotary switch unit is included and that when an engine start is permitted as a result of code matching, a lock of the rotary switch by the above rotary switch lock unit is released. It can prohibit the rotary switch from turning before code matching.
Furthermore, it is preferable that a steering lock unit for mechanically locking the turn of steering is included and that when an engine start is permitted as a result of code matching, a lock of the steering by the above steering lock unit is released. It can keep the steering locked before code matching.
Moreover, it is preferable that a steering lock unit for mechanically locking the turn of the steering and a lock unit mechanically connected to the steering lock unit for mechanically locking the drive of a rotary switch unit are included and that when an engine start is permitted as a result of code matching and a steering lock is not released, the rotary switch is mechanically locked and an engine start is prohibited. This configuration would be able to surely prohibit an engine start if a steering lock is not released through some failure.
It is also preferable that the above keyhole is aligned with the turning axis of a rotary switch.